Conversion of cuprous materials



Patented Mar. 16, 1926..

UNITED STATES PATENT OFFICE.-

COMPANY, or NEW YORK, N. Y.,

A CORPORATION OF NEW YORK.

CONVERSION OF CUPROUS MATERIALS.

No Drawing.

To all whom it may concern:

Be it known that I, MAmoN I-I. Mnmuss, a citizen of the United States, and resident of \Vestbury, Long Island, Nassau County, State of New York, have invented certain new and useful Improvements in the Conversion of Cuprous Materials, of which the following is a specification.

This invention relates to methods or processes for converting black copper or like materials into blister copper.

Black copper as commonly known is a product of the direct smelting of oxidized ores or residues in a blast furnace with a reducing atmosphere. The copper of such material normally amounts to approximately from 74 per cent to 94 per cent with comparatively large percentages of lead, zinc, tin, iron and other impurities. An

analysis of two typical samples of black copper such as may be used with this process reveals the following percentage COlIlPOSltions Also small and generally substantially negligible quantities of sulphur, aluminum oxide, silver and gold are often present.

The process of this invention is also applicable to the reclamation of the copper from brass, bronze and other materials having a composition somewhat analogous to that of black copper, and the conversion of such materials by this process is intended to fall within the scope of the invention disclosed and claimed in this application.

It is an aim of this invention to provide a process for converting black copper or the like materials to blister copper independently of other metallurgical operations. Furthermore, it is also an object of this invention to accomplish such conversion by 'a process which is economical and convenient to practice in connection with a wide variety of ores or other material and the results of which are very dependable.

' Heretofore in most instances black copper Application filed August 1, 1925. Serial No. 47,638.

or like materials have been economically converted to blister copper only by utilizing the excess heat produced in the bessemerizing process of converting copper matte (a mixture of iron sulphide and copper sulphide) or white metal (copper sulphide). The conversion of copper matte is carried out without the application of external heat since the process is in fact exothermic. There are certain classes of materials available in large quantities which mav be added during the conversion of the copper matte to blister copper, 'such materials thus being also simultaneously smelted into the form of blister copper. Among such materials may be lincluded black copper and brass materia s.

However, the combining of the treatment of copper matte with the conversion of black copper often involves serious difliculties. Although the causes of such difficulties are not well understood, it is believed that some of the iron present in large quantities in the matte combines with the zinc of the black copper or brass to form substantial quantities of zinc ferrite, an. extremely infusible material. This material settles out and coats the interior of the converter, particularly the nose thereof, and eventually renders the opening too small for efficient use. It is also thought possible that an infusible incrustation comprising a compound of magnetite, zinc oxide and zinc silicate" may be formed. In any event undesirable incrustations are formed upon the interior of the converter which reduce the available space therein and limit the amount of cold material which may be introduced.

The above described difficulties together with the fact that there is often a supply of brass or black copper in excess of that which may be treated with copper matte, renders it desirable to provide a process for converting such material to blister copper independently of the coppermatte conversion. I have discovered that if the blackcopper or the like metals are given a preliminary or initial heating to. start the operation, suflicient heat can be generated in a converter, by the oxidation of the impurities contained in such metals to enable the conversion of such cuprous metals to blister copper, and according to this invention black copper and the like cuprous metals are converted by subjecting themto an initial or preliminary heating operation sufficient to initiate oxidation of the impurities upon blowing an oxidizing fluid into the mass, and then converting the copper by blowing an oxidizing fluid, such for example as air, into the mass will be particularly pointed out in the zippended claims.

One example of the manner in which the invention may be satisfactorily carried out,

is as follows: The black copper or like material as above described is mixed with from 10 to 25 per cent of coke in a' small red hot converter. The coke comprises fuel for initiating the process, such fuel being ignited by the hot converter, the heated con dition of which also assists in starting the process. A quantity of Wood may also be included for more rapidly igniting the coke and melting the charge.

After the converter is filled with this mixture, the air blower may be turned on with approximately four pounds of pressure for a period of from 15 to 20 minutes. During this time, the converter may be in a position With the flue disconnected. When thecopper material starts to melt and the conver sion reaction sets 'in, fumes will appear at the opening of the converter. The charge within the converter will have settled considerably by this time so that additional material may be introduced into the top thereof.' Thereafter, the converter may be turned back upon its tuyeres' with its opening in a position to discharge fumes through the flue. blower should be adjusted to give a pressure of 5 1 to 6 pounds. At the endof this period the pressure may be increased and maintained -at the full normal working pressure of approximately 9 pounds during a period of about one hour, at which time the charge is brought to the finished condition of blister copper.

In carrying out the above described process for seven similar successive charges in the converter the total amounts of material introduced were as follows:

Pounds. Black copper blocks 14,916 Black copper ingots -l 7,913 Light brick brass 21,650 Oily brass turnings 51,000 Coke 14,000

It is found that the materials introduced in the relative proportions as above, give For the next 10 or 15 minutes thevery satisfactory results both as to quality of the blister copper formed and as to its cost as produced by the process. During the .7 charges above referred to, the coke consumed amounted to approximately 12.9% of the total weight of the charges. It will be understood that more or less coke may be used depending upon the character of the ore or brass being treated. For example if a larger proportion of oily brass turnings were used the 1 amount of fuel necessary :(fllld' be less in View of the fuel value of the o1 The converter and blower equipment used may be of the type ordinarily used in the conversion of copper matte by the bes semerizing process.

The impurities which do not pass off as gaseous oxides form a slag which is preferably rendered liquid by suitable fluxing constituents, so that it can from time, to time be skimmed from the surface orv poured off.

Suitable fluxing constituents are well known in the art and the particular materials used for such purposes will depend upon the nature of the impurities in the ore being treat ed. Irony material may be used to flux the coke ash and silicious materials will serve to flux any iron oxide which may be formed, since the silicate unites With'the oxidized iron to form a liquid ferro-silicate.

As above indicated the materials most suitable for treatment by this process'are black copper, brass or bronze or other copper bearing materials, which should preferably be in heavy pieces so that it may be handled cheaply andexpeditiously and introduced into the converter in large quantities by weight within the limited space available.- Brass or bronze borings and turnings, and fuse parts are suitable for the process. Lighter brass or other materials may also be used, although if their volume is great in proportion to their weight it becomes difficult to charge the converter at an economical rate.

It will be understood that the process may be started by using heat from sources other than by mixing fuel with the charge, for

it may be preferable to introduce the cop er bearing material in the molten form, whet er fuel or the various methods of initial extraneous firing are used. I have found that once the process is initiated, under most conditions there is sufiicient heat given off by the oxidation of the impurities to be formed in these materials, to continue and complete the conversion of the copper con tent to blister copper. The heat produced by the oxidation of lead, zinc, carbon, tin or other impurities having a greater affinit for oxygen than copper, is thus economica After the first charge in the converter has been converted to blister copper, the process may be continued by a form of fractional blowing, that is, a portion of the molten blister copper may be retained in the converter as a heat reservoir. ,More of the cold or partially warmed material with or without fuel may then bevadded and the resultant mixture blown to blister copper again, thereafter an. additional 35 per cent, per cent or per cent of the product, as desired, may be removed and the operation repeated; In this manner, the process of the invention may be carried out. continuously with the use of very little fuel.

While I have described my invention according to the preferred embodiment of the same it will be obvious to those skilled in the art. after understanding my invention, that Various alterations, modifications and substitutions may be made without departing from the scope of the invention, and I aim in the appended claims to cover all such modifications. 1 I

What is claimed as new and is desired to be secured by Letters Patent is: i

1. The method of treating black copper or the like materials embodying impurities which are largely in metallic form to obtain blister copper directly therefrom, which comprises preliminarily heating the mass of black copper or the like until it'is at least partially melted. then blowing air therethrough, controlling the quantity and pressure of the air to effect rapid oxidation of the impurities, and relying substantially upon the heat produced by such oxidation for producing blister copper from the mass.

2. The method of obtaining blister copper directly by treatment of black copper or.

the like materials embodying impurities which are largely in metallic form and a substantial portion of which form gaseous oxides of the metals, which method oomprises preliminarily heating the mass of black copper or the like until it is at least partially melted, then blowing air therethrough in such quantity and at such pressure that rapid oxidation of the impurities is effected, relying substantially upon the heat produced by oxidation of thefmetallic impurities for producing blister cop or from the mass, and removing the resulting metallic oxides from the mass as gases and in slag.

3. The method of obtaining blister copper directly by treatment of black copper containing impurities consisting of metals which form gaseous oxides and lessthan in the neighborhood of 10% of iron, which method comprises preliminarily heating the mass of black copper or the like until it is at least partially melted, then blowing air therethrough in such quantity and at such pressure that rapid oxidation of the impurities is effected, relying substantially uponthe heat produced by oxidation of the metallic impurities for producing blister copper from the mass, and removing the resulting iron oxide in slag and the other metallic oxides as gases. u i

4. The method of 'converting'black copper or the like to blister copper by a bessemerizing process which comprises initiating:

the conversion process by niixingandburning approximately from 10% to25% of car boniferousfuel with the black copper in a converter, and thereafter continuing theprocess to a; conclusion by utilizing the heat resulting from oxidation of impurities in the black copper having a greaterfaiiinity for oxygen than copper.

5. The method of converting into. blister copper various materials containing high percentages of copper and metallic impuria ties such as lead, zinc, tin, iron, etc. which comprises relying substantially solely upon the heat from oxidation of the said metallic impurities and controlling such heat by an air blast to maintain the reaction temperature necessary for the conversion.

6. The method of converting black copper or like materials toblister copper which comprises charging a hot converter with a mixture of the materials with sufiicient fuel to initiate the conversion process,then introducing a gentle air blast, increasing and continuing the blast and utilizing the heat.

from oxidation of the impurities in the mixture to continue and complete the conver sion of the copper content in the charge to blister copper, and removing the slag formed during the process.

7.. The method of converting black copper or like materials to blister copper w a mixture of the material in heavy pieces with sufficient coke as fuel to initiate the. conversion process and fluxlng constituents to liquidize the slag formed, then introducmg a gentle air blast, thereafter increasing the air blast to full normal pressure, continuing the blast and utilizing the heatfrom oxidation'of theimpurities in the mixture to contlnue and complete the conversion of ich comprises charging a red hot converter with to lirluidize the slag formed, then introducing agentle air blast, thereafter increasing the angblast to full normal pressure, and contln'umg the blast and utilizing the heat from oxidation of the impurities in the mixture-to continue and complete the conversion of the copper content to blister copper.

rial in a converter with fluxing constituents to liquidize the slag formed, introducing into the converter a gentle air blast, and increasing and continuing the blast and utilizing the heat from oxidation of the metallic impurities in the mixture to continue and complete the conversion of the copper con tent to blister copper.

10. The method of converting black copper or like materials to blister copper which comprises charging a red hot converter with a mixture of the black copper in heavy pieces with from 10% to 25% of carboniferous fuel to initiate the conversion process, then introducing a gentle air blast, thereafter increasing the air blast to full normal pressure continuing the blast and utilizing the heat from oxidation of the impurities in the mixture to continue and complete the conversion of the copper content to blister copper.

11. The method of converting into blister copper various materials containing high percentages of copper and impurities such emme as lead, zinc, tin, iron, etc., which comprises charging a red hot converter with a mixture of the material in heavy pieces with sufficient coke as fuel to initiate the conversion process, introducing a gentle air blast, thereafter increasing the air blast to full normal pressure, continuing the blast and utilizing the heat from oxidation of the impurities in the mixture to continue and complete the conversion of the copper content to blister copper, and removing the slag formed during the process by rabbling while the copper is still hot.

12. The method of forming blister copper from black copper or the like independently of the conversion of copper bearing sulphur compounds by a bessemerizing process which comprises initiating the conversion process by the use of extraneous litat, then continuing the process to a conclusion by utilizing the heat resulting from oxidation of metallic impurities in the black copper having a greater afiinity for oxygen than copper, and thereafter repeating the process by re moving a portion only of the blister copper and retaining the balance as a heat reservoir to initiate the next cycle of the process.

In testimony whereof I have signed my name to this specification.

MARION H. MERRISS. 

